Try this first
Check that the steam wand tip is clean. Start with cold milk and place the tip just below the surface.
Why this can help
A blocked wand or a tip buried too deeply makes it harder to introduce air.
What to try next
Once the milk expands, lower the tip slightly and create a rolling motion to smooth the texture.
Related skills: Milk and drinks. Explore the Home Barista Roadmap for more context.
Every coffee and setup behaves a little differently. Make one change, taste, and keep the result that works for you.